jpa page

One (local sql query, pay attention to what the table name with the name of both the database for a particular database queries)

public interface UserRepository extends JpaRepository<User, Long> {

  @Query(value = "SELECT * FROM USERS WHERE LASTNAME = ?1",
    countQuery = "SELECT count(*) FROM USERS WHERE LASTNAME = ?1",
    nativeQuery = true)
  Page<User> findByLastname(String lastname, Pageable pageable);
}

 

Act II (jpa has been achieved paging interface for simple paging query)

public interface PagingAndSortingRepository<T, ID extends Serializable>
  extends CrudRepository<T, ID> {

  Iterable<T> findAll(Sort sort);

  Page<T> findAll(Pageable pageable);
}

Accessing the second page of User by a page size of 20 you could simply do something like this:

PagingAndSortingRepository<User, Long> repository = // … get access to a bean
Page<User> users = repository.findAll(new PageRequest(1, 20));

User findFirstByOrderByLastnameAsc();

User findTopByOrderByAgeDesc();

Page<User> queryFirst10ByLastname(String lastname, Pageable pageable);

Slice<User> findTop3ByLastname(String lastname, Pageable pageable);

List<User> findFirst10ByLastname(String lastname, Sort sort);

List<User> findTop10ByLastname(String lastname, Pageable pageable);

 

//service
 Sort sort = new Sort(Sort.Direction.DESC,"createTime"); //创建时间降序排序
 Pageable pageable = new PageRequest(pageNumber,pageSize,sort);
 this.depositRecordRepository.findAllByUserIdIn(userIds,pageable);

//repository
Page<DepositRecord> findAllByUserIdIn(List<Long> userIds,Pageable pageable);

 

 

Act III (Query notes, hql language bureau for the query specified conditions data)

 @Query(value = "select b.roomUid from RoomBoard b where b.userId=:userId and b.lastBoard=true order by  b.createTime desc")
    Page<String> findRoomUidsByUserIdPageable(@Param("userId") long userId, Pageable pageable);

Pageable pageable = new PageRequest(pageNumber,pageSize);
Page<String> page = this.roomBoardRepository.findRoomUidsByUserIdPageable(userId,pageable);
List<String> roomUids = page.getContent();

Can customize the entire entity (Page <User>), the query may be a few fields (Page <Object []>), and native sql almost the same flexibility.

 

And France (expansion findAll, suitable for dynamic sql queries)

public interface UserRepository extends JpaRepository<User, Long> {

    Page<User> findAll(Specification<User> spec, Pageable pageable);
} 

@Service 
public class UserService { 

    @Autowired 
    Private UserRepository userRepository; 

    public Page <the User> getUsersPage (PageParam pageParam, NICKNAME String) { 
        // specification defines 
        Specification <the User> = new new Specification Specification <the User> () { 

            / ** 
             * configuration assertion 
             * @param root entity object references 
             * @param query rule query object 
             * @param cb rule to build the object 
             * @return assertion 
             * / 
            @Override 
            public Predicate toPredicate (Root <the User> root, CriteriaQuery <?> query, CriteriaBuilder cb) { 
                List <Predicate> predicates = new ArrayList < > ();// All assertions
                if (StringUtils.isNotBlank (nickName)) { // add assert 
                    the Predicate likeNickName = cb.like (root.get ( "NICKNAME") AS (String.class), NICKNAME + "%."); 
                    predicates.add (likeNickName); 
                } 
                return cb.and (predicates.toArray (new new the Predicate [0])); 
            } 
        }; 
        // paging information 
        Pageable pageable = new PageRequest (pageParam.getPage ( ) - 1, pageParam.getLimit ()); // page: Starting from the front end 1, jpa from zero, to be converted 
        // query 
        return this.userRepository.findAll (Specification, Pageable); 
    } 

}

 

Five of (use entityManager, suitable for dynamic sql queries)

@Service
@Transactional
public class IncomeService{

    /**
     * 实体管理对象
     */
    @PersistenceContext
    EntityManager entityManager;

    public Page<IncomeDaily> findIncomeDailysByPage(PageParam pageParam, String cpId, String appId, Date start, Date end, String sp) {
        StringBuilder countSelectSql = new StringBuilder();
        countSelectSql.append("select count(*) from IncomeDaily po where 1=1 ");

        StringBuilder selectSql = new StringBuilder();
        selectSql.append("from IncomeDaily po where 1=1 ");

        Map<String,Object> params = new HashMap<>();
        StringBuilder whereSql = new StringBuilder();
        if(StringUtils.isNotBlank(cpId)){
            whereSql.append(" and cpId=:cpId ");
            params.put("cpId",cpId);
        }
        if(StringUtils.isNotBlank(appId)){
            whereSql.append(" and appId=:appId ");
            params.put("appId",appId);
        }
        if(StringUtils.isNotBlank(sp)){
            whereSql.append(" and sp=:sp ");
            params.put("sp",sp);
        }
        if (start == null)
        {
            start = DateUtil.getStartOfDate(new Date());
        }
        whereSql.append(" and po.bizDate >= :startTime");
        params.put("startTime", start);

        if (end != null)
        {
            whereSql.append(" and po.bizDate <= :endTime");
            params.put("endTime", end);
        }

        String countSql = new StringBuilder().append(countSelectSql).append(whereSql).toString();
        Query countQuery = this.entityManager.createQuery(countSql,Long.class);
        this.setParameters(countQuery,params);
        Long count = (Long) countQuery.getSingleResult();

        String querySql = new StringBuilder().append(selectSql).append(whereSql).toString();
        Query query = this.entityManager.createQuery(querySql,IncomeDaily.class);
        this.setParameters(query,params);
        if(pageParam != null){ //分页
            query.setFirstResult(pageParam.getStart());
            query.setMaxResults(pageParam.getLength());
        }

        List<IncomeDaily> incomeDailyList = query.getResultList();
      if(pageParam != null) { //分页
            Pageable pageable = new PageRequest(pageParam.getPage(), pageParam.getLength());
            Page<IncomeDaily> incomeDailyPage = new PageImpl<IncomeDaily>(incomeDailyList, pageable, count);
            return incomeDailyPage;
        }else{ //不分页
            return new PageImpl<IncomeDaily>(incomeDailyList);
        }
    }

    /**
     * 给hql参数设置值
     * @param query 查询
     * @param params 参数
     */
    private void setParameters(Query query,Map<String,Object> params){
        for(Map.Entry<String,Object> entry:params.entrySet()){
            query.setParameter(entry.getKey(),entry.getValue());
        }
    }
}